Schizoid personality disorder is an uncommon condition in which people avoid social activities and consistently shy away from interaction with others. It affects more males than females. If you have schizoid personality disorder, you may be seen as a loner, and you may lack the desire or skill to form close personal relationships.

To others, you may appear somewhat dull or humorless. Because you don't tend to show emotion, you may appear as though you don't care about what's going on around you. Although you may seem aloof, you may actually feel lonely, even if it's hard for you to acknowledge. Or you may feel much more at ease being alone, and feel comfortable with your life.

The cause of schizoid personality disorder is unknown. Therapy and — in some cases — medications can help.

People with schizoid personality disorder are loners. If you have this condition, you're likely to:

Prefer being alone and usually choose solitary activities

Prize independence and have few close friendships

Feel confused about how to respond to normal social cues and generally have little to say

Feel little if any desire for sexual relationships

Feel unable to experience pleasure

Come off as dull, indifferent or emotionally cold

Feel unmotivated and tend to underperform at school or work

Personality disorders begin in early adulthood, at the latest. Some of these tendencies may have first become noticeable during your childhood. They also occur across a range of social and personal situations. They may either cause you to have trouble functioning well in a job, socially or in other areas of life. However, you may do reasonably well in your job if you mostly work alone.

If you have schizoid personality disorder, you may not know how to form friendships, or you may feel too anxious around other people to try, so you simply give up and turn inward.

Schizophrenic spectrum

Schizoid personality disorder is considered part of the schizophrenic spectrum of disorders, which includes schizotypal personality disorder and schizophrenia. These conditions all have similar symptoms, such as a severely limited ability to make social connections along with a lack of emotional expression.

However, unlike schizotypal personality disorder and schizophrenia, people with schizoid personality disorder:

Are in touch with reality — they're unlikely to experience paranoia or hallucinations

Make sense when they speak, although the tone may not be animated — in contrast to conversational patterns of someone with schizotypal personality disorder or schizophrenia, which are typically strange and hard to follow

Classes of personality disorders

Another way of understanding personality disorders has been to group them into classes. Schizoid personality disorder, along with schizotypal and paranoid personality disorders, are grouped together as Class A personality disorders. Class A disorders refer to odd or eccentric behaviors. They differ from Class B — dramatic and emotional behaviors — and Class C — anxious and fearful behaviors.

When to see a doctor

Treatment for schizoid personality disorder is usually sought by people who are bothered by an associated problem, such as depression. In cases where the isolation is bothersome or the other symptoms are distressing, psychotherapy may be helpful.

If someone close to you has urged you to seek help for symptoms common to schizoid personality disorder, make an appointment, starting with a primary care physician or mental health professional.

If you suspect a loved one may have schizoid personality disorder, gently suggest that the person seek medical attention. It might help to offer to go with him or her to the first appointment.

The exact causes of schizoid personality disorder are unknown, although a combination of genetic and environmental factors — particularly in early childhood — are thought to increase the risk of developing the disorder.

You're likely to start by first seeing your family doctor or a general practitioner. However, in some cases when you call to set up an appointment, you may be referred directly to a psychiatrist.

What you can do

To prepare for your appointment, make a list of:

Any symptoms you or your family has noticed. Include how long you've had the symptoms.

Key personal information. Include any traumatic events in your past and current, major stressors.

Your medical information. Includeother physical or mental health conditions, as well as family history.

All medications and doses. Include prescription and nonprescription drugs, vitamins, or other supplements that you're taking.

Questions to ask your doctor. Having a list prepared can help you make the most of your time together.

Take a family member or friend along, if possible. Someone who has known you for a long time may be able to ask questions or share information with the doctor that you don't remember to bring up.

Some basic questions to ask your doctor include:

What is likely causing my symptoms or condition?

What are other possible causes?

Is my condition likely temporary or long term?

How could treatment help me?

What types of treatments may be effective for me?

Are there medications that can help?

If you're recommending medications, what are the possible side effects?

How much can I expect my symptoms to improve with treatment?

I have other health conditions. How can I best manage them together?

Are there brochures or other printed materials that I can have? What websites do you recommend?

In addition to the questions you've prepared, don't hesitate to ask other questions during your appointment.

What to expect from your doctor

To start a discussion about your mental health, your doctor may ask questions such as:

What are the problems or symptoms that concern you?

How much do these symptoms bother you?

Have you noticed that your symptoms get worse in certain situations? If yes, what are those situations, and how do you handle them?

Do you have close friends or family? If no, does it bother you?

How would you describe yourself?

Do you frequently choose to do things by yourself?

Do you confide in anyone who is not in your immediate family?

What do you prefer to do in your free time?

Have you ever thought about harming yourself or others? Have you ever actually done so?

Have your family members or friends expressed concern about your behavior?

Have any of your close relatives been diagnosed with or treated for mental illness?

Do you drink alcohol or use drugs? If so, how often?

Diagnosing schizoid personality disorder is usually based on an in-depth interview with your doctor about your symptoms as well as your medical and personal history. Your doctor may perform a physical exam to rule out other conditions that may be causing or contributing to your symptoms. If your initial visit is with a primary care doctor, you'll likely be referred to a mental health professional for further evaluation.

To be diagnosed with schizoid personality disorder, you must meet criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association. Diagnosis of schizoid personality disorder includes four or more of these characteristics:

You neither desire nor enjoy close relationships, including being part of a family.

You almost always choose solitary activities.

You have little, if any, interest in sexual experiences with another person.

You take pleasure in few, if any, activities.

You don't have any close friends or confidants other than first-degree relatives.

You seem not to care about praise or criticism.

You seem emotionally cold, detached or unexpressive.

For schizoid personality disorder to be diagnosed, doctors need to rule out conditions with similar symptoms.

If you have schizoid personality disorder, you may prefer to go your own way and avoid interacting with others, including doctors. You may be so used to a life without emotional closeness that you're not sure you want to change — or that you can.

You might agree to start treatment only at the urging of a family member who is concerned about you. But professional help from a therapist who's experienced in treating schizoid personality disorder can have a major positive impact. Treatment options include:

Medications. Although there's no specific drug to treat schizoid personality disorder, certain drugs can help with symptoms. For example, if you have symptoms of anxiety or depression, you doctor may prescribe a selective serotonin reuptake inhibitor (SSRI). Or while antipsychotics are not a routine part of treatment, they may be used to help with flattened emotions and social problems.

Talk therapy (psychotherapy). If you feel that you would like to have closer relationships, a modified form of cognitive behavioral therapy may help you change the beliefs and behaviors that are problems for you. A therapist with experience treating schizoid personality disorder is likely to understand your need for personal space and how difficult it is for you to open up about your inner life. He or she can continue reaching out to you without pushing too hard.

Group therapy. A goal of individual treatment may be a group setting in which you can interact with others who are also practicing new interpersonal skills. In time, group therapy may also provide a support structure and increase your social motivation.

With appropriate treatment and a skilled therapist, you can make significant progress and improve your quality of life.

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